diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 517dfa8fd31..be8df2937df 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -2067,6 +2067,7 @@ class MailThread(models.AbstractModel):
                 partner_ids=[(4, pid) for pid in partner_ids],
                 auto_delete=True,
                 auto_delete_message=True,
+                parent_id=False, # override accidental context defaults
                 subtype_id=self.env.ref('mail.mt_note').id)
 
     @api.multi